Most search engines and especially Google do not like hidden text and links and encourages you to avoid them completely.  Since Auto PlusXP allows you to change the font size, type and color, you should follow these rules. Google recently posted an official guideline:

Hiding text or links in your content can cause your site to be perceived as untrustworthy since it presents information to search engines differently than to visitors. Text (such as excessive keywords) can be hidden in several ways, including:

  • Using white text on a white background
  • Including text behind an image
  • Using CSS to hide text
  • Setting the font size to 0

Hidden links are links that are intended to be crawled by Googlebot, but are unreadable to humans because:

  • The link consists of hidden text (for example, the text color and background color are identical).
  • CSS has been used to make tiny hyperlinks, as little as one pixel high.
  • The link is hidden in a small character - for example, a hyphen in the middle of a paragraph.

Read the entire Google guideline here.